• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.450-453
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• 1999

In this paper, The relationship between device performance and channel length(1.5-50$\mu$m) in polysilicon thin-film transistors fabricated by SPC technology was Investigated by measuring electric Properties such as 1-V characteristics, field effect mobility, threshold voltage, subthreshold swing, and trap density in grain boundary with channel length. The drain current at ON-state increases with decreasing channel length due to increase of the drain field, while OFF-state current (leakage current) is independent of channel length. The field effect mobility decrease with channel length due to decreasing carrier life time by the avalanche injection of the carrier at high drain field. The threshold voltage and subthreshold swing decrease with channel length, and then increase in 1.5 $\mu$m increase of increase of trap density in grain boundary by impact ionization.

• 전기의세계
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• v.22 no.5
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• pp.19-32
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• 1973

This paper treats with some of plasma jet behaviors under magnetic field for the purpose of controlling important characteristics of plasma jet in the practices of material manufacturings. Under the existence and non-existence of magnetic field, the pressure distribution, flame length, stability and noise of plasma jet are comparatively evaluated in respect of such parameters as are current, gap of electrode, quantity of argon flow, magnetic flux density, diameter and length of nozzle. The results are as follows: 1) the pressure, the length and the noise of plasma jet rise gradually with the increase of are current, and have high values under identical arc current as the diameter of nozzle increases, but reverse phenomenon tends to appear in the noise. 2) The pressure, the flame length and the noise increase with the increased quantity of argon flow, and the rising slope of noise is particularly steep. Under magnetic field, the quantity of argon flow in respect of flame length has the critical value of 80(cfh). 3) The pressure and length of flame decrease with small gradient value as the length of gap increases, but the noise tends to grow according to the increase of nozzle diameter. 4) The pressure and the length of jet flame decrease inversly with the increase of magnetic flux density, which have one critical value in the 100 amps of arc current and two values in 50 amps. The pressure of jet flame can be below atomospher pressure in strong magnetic field. 5) "The constriction length of nozzle has respectively the critical value of 6(mm) for pressure and 23(mm) for the length of flame. 6) Fluctuations in the wave form of voltage become greater with the increase of argon flow and magnetic flux density, but tends to decrease as arc current increases, having the frequency range of 3-8KHz. The wave form of noise changes almost in parallel with that of voltage and its changing value increases with argon flow, arc current and magnetic flux density, having the freuqency range of 6-8KHz. The fluctuation of jet presurre is reduced with the increase of argon flow and magnetic flux density and grows with arc current.rent.

• Journal of Korean Society on Water Environment
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• v.24 no.5
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• pp.569-580
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• 2008

In this study, area-weighted slope and slope length module, considering measured field slope and slope length of the agricultural fields within the subwatershed, was developed using the ArcView Avenue programming to reflect the field topography of the Soil and Water Assessment Tool (SWAT) HRU in simulating the hydrology and water quality. Flow and sediment yield estimated values of the SWAT were compared with and without applying area-weighted slope and slope length module, developed in this study. There was 103% increases in estimated sediment with area-weighted slope and slope length module for the study watershed. The soil erosion and sediment yield from only agricultural field in Hae-an watershed was also assessed. There are 111% increase in estimated soil erosion and 112% increase in estimated sediment by applying area-weighted slope and slope length module. This study shows that the area-weighted slope and slope length module needs to be utilized in estimating the HRU field slope and slope length for accurate estimation of soil erosion and nonponit source pollutant modeling with the SWAT although it is not feasible to measure topographic information for every agricultural fields within the watershed. The area-weighted slope and slope length module can be used in identifying soil erosion hot spot areas for developing cost effective and efficient soil erosion management practices.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.319-323
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• 1991

To determine how closely related to field lodging for several characters affecting the field lodging for several characters affecting field lodging, and to obtain the basic information for selection of lodging resistance genotype, an experiment was conducted with 10 varieties from May to Oct., 1990 at the experimental field in Sunchon Xational University. Culm length, dry weight per unit culm length (W/1), bending moment per unit culm diameter (W1/d), lodging index (L), bending load ratio (W1/P), and index of critical lodging load(W$_{s}$$^{2}$/1$^4$) were the most closely related characters to field lodging. Culm length showed highly significant positive correlation coefficient with field lodging(r=0.7607), but it may be undesirable to judge lodging resistance of genotype by culm length itself without consideration of culm stiffness. Considering the difficulty and time-consuming to measure the character, clum length, W/1, W1/d, and W$_{s}$$^{2}$/1$^4$ were easy to measure and hence would be the most useful variables to judge the lodging resistance of genotype. Culm diameter, cross sectional area of culm, thickness of culm wall, and the second inertia moment of cross section of culm were not correlated with field lodging at all. Breaking strength of culm showed significantly negative correlation coefficient (r=-0.3986) with field lodging.ing.

• 한국연소학회:학술대회논문집
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• 2006.04a
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• pp.105-110
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• 2006

Many previous works have been performed to provide correlations of flame length, theoretically and experimentally. Most of these results studied were conducted in vertical turbulent flame with no coaxial air condition. The present study analyzes the flame length scaling with coaxial air. In turbulent hydrogen non-premixed jet flames with coaxial air, flame length scaling theoretically proposed so far has been related with the concept of a far-field equivalent source. At high coaxial air to fuel velocity ratio, $U_A/U_F$, however, this scaling theory has some difference with experimental flame length data. This difference is understood to be due to the fact that the theory is based on far-field notion, while the effect of coaxial air on jet flame occurs in the region near the nozzle exit. Therefore, we define effective jet density $P_{eff}$ involving the concept of near-field so that effective jet diameter can be extended to the near-field region. In this condition, we modify the correlation and compare with experimental data.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.1
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• pp.47-52
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• 2007

Organic field-effect transistors (OFETS) are of interest for use in widely area electronic applications. We fabricated a copper phthalocyanine (CuPc) based field-effect transistor with varying channel length. The CuPc FET device was made a top-contact type and the channel length was a $100\;{\mu}m,\;50\;{\mu}m,\;40\;{\mu}m,\;and\;30\;{\mu}m$ and the channel width was a fixed at 3 mm. We observed a typical current-voltage (I-V) characteristics in CuPc FET with varying channel length (L) and we calculated the effective mobility. Also, we measured a capacitance-voltage (C-V) by applied bias voltage with varying frequency at 43, 100, 1000 Hz.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.96-100
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• 2007

Condenser lens and objective lens are used to demagnify the image of the crossover to the final spot size. In lens, electrons are focused by magnetic fields. This fields is fringing field. It is important in electron focusing. Electron focusing occurs the radial component field and axial component field. Radial component produces rotational force and axial component produces radial force. Radial force causes the electron's trajectory to curve toward the optic axis and corss it. Focal length decreases as the current of lens increases. In this paper, we use the focal length for desiging the hardware of lens current control and present the results.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.11
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• pp.1048-1055
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• 2005

The formula to calculate a variation of optical path length of single crystal by the electric field was derived by this study. The formula was applied to $Bi_{12}SiO_{20}$ single crystal. The results are as follows. In case of the applied electric field in the body diagonal direction and the passing light along the same direction, the variation of optical path length had the largest value. The symmetry of the space distribution of optical path length satisfied $E3C_2\;8C_3$, the set of elements of the symmetry of $Bi_{12}SiO_{20}$ single crystal. The property which gave the largest influence to the variation of optical path length is the strain of length by the Inverse piezoelectric effect. The second influence, is the variation of the refractive index by the electro-optic effect. The variation of optical path length by the inverse piezoelectric effect and by the electro-optic effect have a reverse sign each other.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.859-860
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• 2009

• International Journal of Highway Engineering
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• v.16 no.3
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• pp.51-57
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• 2014

PURPOSES : This study is to suggest tunnel length to spray curing compound, based on the field tests. METHODS : At first field test, length from the entrance of tunnel to wet wall was checked by visual survey. The second and third test, various sensors were installed in concrete or in tunnel, such as RH sensor, temperature sensor, portable weather station and etc.. And also, test for bleeding and retaining water of concrete were conducted to evaluate environmental effect on concrete pavement. RESULTS : The result of the field experiment for tunnel length to spray curing compound indicates that length changes depending on tunnel length, season, and location. Environmental condition of a short tunnel was not much different between location near entrance and at center of tunnel. However, in case of a medium and long tunnel, effect of outside environmental condition decreased, when location moved into tunnel center of it. CONCLUSIONS : From the testing results, it can be proposed that optimum tunnel length to spray curing compound is 60m for a medium and long tunnel, and whole length for a short tunnel.